Whether or not you can put "magna cum laude" on your resume depends on your university's specific GPA requirements for that distinction. A 3.89 GPA is *very* likely to qualify you for magna cum laude at most universities, but it's
not guaranteed. Some universities have higher cutoffs or other criteria beyond GPA.
Check your university's official guidelines. Look at your university's website or your graduation materials to find the exact GPA requirements for magna cum laude. Only then can you definitively say if you qualify. If you do qualify, then yes, it's appropriate to include it on your resume.