The solution will be to use an associated module through your category listing content menu's configuration page, reading that
tutorial
will probably help you :
A category listing menu is only displaying the categories by itself, so that's why there the "Associated modules" option. Once you display once your menu on your front end, you should get a products listing module generated automatically and added to that "Associated modules" option. That's this module which will display the products listing under the categories. So, you can personalize the listing of the products by going in the menu Display->Content modules and editing the module associated to the menu you created OR by just clicking on the link of the module in that "Associated modules" option. You will again see lots of options to configure your products listing the way you want it.