The Fighting Sioux name relates to the Dakota, Lakota and Nakota warriors who ruled the northern plains more than a hundred years ago. It's not a reference to the Sioux people today. It's a reference to the Sioux warriors who long ago fought to defend their land and their way of life.
How do I know this? Because I can look at the logo as a point of reference. The person shown in the logo is clearly an idealized, fictitious Sioux warrior. He doesn't look anything like you or the American Indians I see on campus every day.
The logo isn't intended to represent you any more than the Vikings logo or the Fighting Irish name is intended to represent me.