O'Neill was unimpressed with the manner of the defeat at Everton and Vaughan says the squad know what is required of them.
"Obviously the manager was disappointed with the performance on Monday, and rightly so," said the midfielder to safc.com.
"He will want the players to show we are better than that and we must give him the response he's looking for.
"He demands things from the players and doesn't let standards drop too low for too long.
"Hopefully we can repay his faith and get three points on Saturday.