Forest are one of the few teams to have rattled the Reds this season, beating them at Anfield earlier in the term.
As they prepare to battle the league leaders at home, Williams acknowledged the importance of the game.
Williams told BBC Radio Nottingham: "We are still only halfway through the season, we have still got a lot more to give.
"We are just taking each game as it comes. For us now the focus is on Luton in the FA Cup. Then it is Liverpool, which will be a tough test, but the confidence is flowing through the group now and hopefully we can carry on that winning form.
"It will be special for the whole team, we are up there, we are the only team to beat them this season so hopefully we can do that again.
"But it's going to be tough, we know how good they are, they are probably one of the best teams in the world right now, but with our confidence, our winning form, our 12th man, which is the fans, if that all comes together than we will have a chance."