Network for Public Education is mounting a campaign and encouraging educators and other concerned citizens to contact their Senator. Find a sample letter and the addresses of all Senators at https://actionnetwork.org/letters/tell-your-senator-to-vote-no-for-betsy-devos?source=facebook&. Or write your own letter, in your own words.
Another option is to call 202-225-3121 and be connected with any congressional member, both Senators and Members of the House of Representatives. Tell the staffer who answers that you are opposed to Mrs. DeVos' confirmation as Secretary of Education. They will ask for your name and zip code and tally your call as a "yay" or "nay."