Let's start with the definition of each term, and then an example of each device as it is used in Salinger's novel.
Cliche: a cliche is a trite, overused expression (like "hitting the nail on the head.") Mr. Spencer often uses cliches, such as this line from Ch 2:
"Life is a game that one plays according to the rules."
Colloquialism: common, informal speech. Of course, Holden uses colloquialisms all the time. Here's an example from Ch. 6:
"All morons hate it when you call them a moron."
Sarcasm: language that is intended to insult or harm someone emotionally. Holden is often sarcastic. From Chapter 3:
He said he talked to Jesus all the time. Even when he was driving in his car. That killed me. I can just see the big phony bastard shifting into first gear and asking Jesus to send him a few more stiffs.
Diction: Diction simply means the speaker's style and tone. Holden's diction includes all of the other literary devices listed above. An example of his diction, from Chapter 8:
Sensitive. That killed me. That guy Morrow was about as sensitive as a toilet seat.
The novel is full of all of these... For one, Holden uses cliches to describe just about anything. He says that Jane played checkers by Keeping all Her Kings in the Back Row..... He repeats this over and over.... Also, colloquialisms.... He uses them constantly... Common language..... Phrases such as "I beat it out of there." "She was lousy with rocks" and just a few. Also, Holden is sarcastic...Expecially when he's talking to Stradlater and Ackely. He calls Ackley a Prince, a Gentleman, and Scholar..... Not everyone in the novel is tuned into is sarcasm.