I know that greek life is not looked upon very highly at my school, but we are trying to change that. My chapter has a Teacher Appreciation Day and a Staff Appreciation Day where we bake cookies and set them out in the lounges, offices, etc. with a little table topper that says they are from Alpha Xi Delta and we wanted to let them know how much we appreciate all they do for us and other students. No one has done this before and we recieved very good comments from many professors and administrators. Try doing something like that. I know our consultant told us that one chapter goes out and washes all the car windows in the staff parking lot and leaves a little note on the winshield.
However, no one hates Greek Life here more than the coaches. My boyfriend is on the soccer team and his coach always tells the freshmen to stay away from greek life and don't go down to the houses. Several sisters of mine are on the basketball team and thier coach makes their lives living hell when she finds out. It is very unfortunate beacuse some of our best athletes are members of Greek Life.
All I can say is, it's up to you to improve your image. Something as simple as plates of cookies have made a difference for us, so it could for you, too!