What are some literary devices used in Macbeth, act 1, scene 5, 40-75?

In this passage of the play, Lady Macbeth plots the murder of King Duncan, who is coming to her home to celebrate his victory in the war, and to honour Macbeth's role in that victory. Moments before hearing of Duncan's imminent arrival, she has learned that Macbeth has met with three witches, who have predicted that he will one day be king.
At the beginning of the passage Lady Macbeth delivers her first soliloquy. A soliloquy is a form of speech in which the character is speaking to him or herself, with no intended audience, and thus we can trust that the words they speak are a truthful reflection of their thoughts. The soliloquy begins with the image of the raven, which is a scavenger bird and often a symbol of death. Lady Macbeth references it here to imply that Duncan's death is imminent.
Lady Macbeth uses in her soliloquy lots of metaphorical language. She asks the spirits to "fill (her) from the crown to the toe top-full / Of direst cruelty" and to "make thick (her) blood." In other words she wants to be completely full of cruelty so that not even a trace of compassion remains. Blood is here a symbol for sensitivity and empathy, so Lady Macbeth is also asking, metaphorically, for her blood to thicken so that she will not be able to feel or empathize with the pain of others. She is preparing herself to be able to murder Duncan.
There is also in this soliloquy a recurring motif of darkness. Lady Macbeth asks the darkness to come ("Come, thick night") so that she can murder Duncan without herself or the heavens seeing what she is doing. Darkness also of course is a familiar symbol of evil and immorality, so when Lady Macbeth repeatedly calls upon it, the audience is able to infer that this is an evil, immoral character.
When Macbeth enters the scene, Lady Macbeth immediately tries to persuade him to help her murder Duncan, so that he can be king, and she can be queen. She tells Macbeth to "Look like the innocent flower, / But be the serpent under't." The first part of this instruction is a simile. She wants Macbeth to look innocent and harmless, like a flower, so that Duncan won't suspect the murder. In the second half of the instruction, Lady Macbeth tells Macbeth to, metaphorically, become a snake. A snake, ever since the biblical story of the garden of Eden, symbolizes evil and treachery, so Lady Macbeth is instructing her husband here to have (beneath the false appearance of innocence) murderous, evil intentions, like the snake.
Macbeth, of course, follows his wife's instructions, and as the play progresses, he becomes more and more like the snake. He lies, betrays friends and is treacherous, and by the end of the play is arguably a personification of the evil which his wife summons in this passage from act 1, scene 5.