Purdue University has a page where you can enter a major, graduation date and loan amount to get a payment schedule based on expected pay.
It looks like the major only matters for estimating the wage. Get a $70,000 English job at graduation and your payments will be the same or more than the engineering grads.
I was wrong. Different majors do have different payback percentages even if you do enter the same salary for both. Art history=3.92%, electrical engineering=2.74%.