As a sophomore, he became the starter in the second game of the season, leading the team to an 8–3 record and a win in the Kanza Bowl over the University of Central Missouri.

As a junior, he helped the team reach the NCAA Semifinal for the first time in school history.

[1] Vaughan was signed as an undrafted free agent by the Dallas Cowboys after the 2014 NFL draft.

On September 5, 2015, he was waived after the team decided to carry just two quarterbacks on the regular season roster.

[4] The Cowboys opted not to add him to the practice squad, choosing instead to sign quarterback Kellen Moore, who had previous experience with the team's offensive coordinator Scott Linehan.

[5] On October 19, he was released by the Bills to make room for wide receiver Titus Davis.

[6] On August 28, he was waived-injured by the Steelers after suffering a thumb fracture in a preseason game against the Philadelphia Eagles[7] and on September 2, he was released from injured reserve after reaching an injury settlement.

Between 2018 and 2019, Vaughan was president of a seasonal and supplemental quarterback training program called QB Country.