The attacking winger has penned a one-year deal at the Banks's Stadium which includes the option of a further 12 months.
Sawyers spent the back end of last season on loan with the Saddlers but only managed to register four brief substitute appearances.
Manager Dean Smith said: "Having had him here on loan at the end of last season, he is obviously a player that we know a lot about. He didn't get the minutes on the pitch during that time because of the good run we were on, but he is a player with a lot of potential.
"When he got released by Albion we invited him back here and since then he has displayed an excellent attitude and work-rate and has done well in his outings so far.
"I am pleased to be able to give him this opportunity and I look forward to helping to bring the best out of him."
Sawyers will likely get a run-out in Saturday's latest home pre-season friendly against Leeds.
The 21-year-old said: "This is a good opportunity for me. There is a nice mix of young and experienced players here and I have fitted in well.
"This is a nice environment to work and develop as a player. The gaffer has been good to me and I am looking forward to working with him and the rest of the coaching staff here.
"It was an easy decision to come here and I am determined to take the chance that has been given to me."