Custom category image in /listings-category/xy/xy

When I attach an image to the first listing in any category, it`s used as header image (<div class="landing_image"> and img class="shadow wp-post-image") for the given category (http://domain.com/listings-category/cat1/cat2/)

So for me that is useless to have an image of a listing in top of the category.

Is it possible to change / upload an image for a category?

Can anybody help with this issue?