The Making of Star Trek
does suggest that the actors had a pretty clear sense of what controls performed what function. There's an anecdote about an actor refusing a director's instruction to push a certain button because it was the wrong one for the particular function (and might've blown up the ship), but the actor was probably joking around.
For the abortive Phase II
TV revival that evolved into Star Trek: The Motion Picture
, the technical staff actually put together an Enterprise Flight Manual
containing detailed diagrams of the key stations in the various sets and explanations of what sets of controls were meant to perform what functions.