Cue is more widely used than queue in all meanings, but careful speakers and writers continue to distinguish between them. A queue refers to a braid of hair and to a file, or line: "She wore her hair in a queue which hung down to her waist." "Let's queue up for the next bus." A cue refers in the theater to an indication of following action or speech and in general use to any kind of hint or suggestion; in games, cue means the tipped rod used in billiards and pool: "I don't have a single cue as to his intentions." "When he missed the shot, the player broke his cue in anger."
Dictionary of problem words and expressions. Harry Shaw. 1975.