It's not significantly higher. And we are talking about the population as a whole. I'm refuting the point that "many more women than men are college educated now". This is incorrect. See my other response regarding incidence vs. prevalence.
But we should not be talking about the population as a whole - just the 25-35 year-old segment who are in the dating pool. And in that age group, college-educated women may outnumber men.
They have to, and by a significant margin, for the trends in the graph on the OP's source to obtain.