The defeat was Swansea's heaviest in the league for more than a decade.
"We owe the fans an apology because they travel all that way and we play like that - it's a disgrace," said Dutch international Vorm.
"I've played a lot of games in my career already but this is probably the worst.
"As a team you win and lose with each other, but when you have the privilege to play at Anfield against Liverpool in front of their amazing supporters, on a nice pitch, in good conditions and you play like that then you don't deserve to play at Anfield.
"We showed this year what we are capable of against the big teams but our mentality was so poor.
"I hope it's just an accident because we could have lost 10-0 and if you play like that against smaller clubs we will get beat."