Vaughn was originally scheduled to direct the X-Men: The Last Stand back in 2006, but dropped out over creative differences, leaving Brett Ratner to take over the project..
The Kick-Ass director later signed up to helm the new X-Men reboot, and claims his decision was due to being able to start the franchise from scratch.
"On X-Men: The Last Stand it was cast and I just had to tell the story," Vaughn explained to Empire. "Here we have to recast every role, recreate the sixties, which is not easy, and redesign everything."
"I wasn't trying to cast the young Patrick [Stewart] or Ian [McKellen]," Vaughn continued. "I was trying to cast the young Professor X and Magneto - what those characters are in my mind."
"Hopefully there will be a lot more of this version of the franchise," the director added.
X-Men: First Class will be released in cinemas on June 2.