Macbeth does personify evil in this play because he does commit regicide, not to mention killing his best friend, a wife and her children, and other innocent people.
Beyond this, we can find evil in other aspects of the play as well.
Even though she dies from guilt, Lady Macbeth is the chief instigator to the initial killing of the king. She argues with Macbeth and manipulates into commiting a crime that he knows he should not commit. Her lines in Act I, scene 7 shows how she calls him a coward and presses him to do it for her love.
Was the hope drunk
Wherein you dress'd yourself? hath it slept since?
And wakes it now, to look so green and pale
At what it did so freely? From this time
Such I account thy love. Art thou afeard
To be the same in thine own act and valour
As thou art in desire? Wouldst thou have that
Which thou esteem'st the ornament of life,
And live a coward in thine own esteem,
Letting 'I dare not' wait upon 'I would,'
Like the poor cat i' the adage?
Her greed is definitely a sign of evil in the play.
Another sign of evil is Shakespeare's introduction of the witches. They are referred to as "instruments of darkness." Beyond this, the reader knows from their discussion of torturing the ship's pilot that the witches mean nobody any good. They are the ones that plant the seed in Macbeth, the seed that makes him want to be King when perhaps he had not thought about it before.