Figurative language is language that goes behind the literal and factual to add color and interest to a story.
In "A Good Man is Hard to Find," O'Connor uses the figurative device of simile to describe Bailey's wife. A simile is a comparison that uses the words "like" or "as." In the quote below, O'Connor uses two similes to describe the mother, stating that her
face was as broad and innocent as a cabbage and was tied around with a green head-kerchief that had two points on the top like rabbit’s ears.
In another example of simile, the grandmother's bag is compared to a hippo's head:
She had her big black valise that looked like the head of a hippopotamus in one corner
All of these similes add a comic light-heartedness to the beginning of the story.
O'Connor also uses the literary device of indirect dialogue. This is when a character's speech is reported rather than recorded exactly. Therefore, it is not put in quotation marks. This both speeds a story along—by summarizing dialogue—and also catches the rhythms and cadences of a particular character's voice and personality. In the passage below, O'Connor uses indirect dialogue to capture the feeling of the grandmother's speech:
[She] recalled an old plantation that she had visited in this neighborhood once when she was a young lady. She said the house had six white columns across the front and that there was an avenue of oaks leading up to it and two little wooden trellis arbors on either side in front where you sat down with your suitor after a stroll in the garden. She recalled exactly which road to turn off to get to it.
We have heard enough of the grandmother's direct dialogue, and we have enough understanding of her nostalgia for times past, that it makes perfect sense that she would say all this and want to manipulate Bailey into turning off the main road to find this place. She also uses visual imagery as she describes the oaks and the wooden trellises: we can picture this scene in our mind's eye.