These charts are from a recent survey by the Morning Consult Poll. They questioned 141,400 registered United States voters about whether they approved or disapproved of the senators in their own state. The survey was done between April 1st and June 18th. The margin of error for each state is on the right in the charts.
A note of caution. These numbers only show how popular each senator is in his or her own state. Their popularity in the country as a whole could be far different.