Replace category title with image

This is for a website created on the WordPress platform for the company I work at.

We want to replace the blog category “page title” with a single image for all of the category pages. Preferably – we would like to do this without the use of a plugin.

Below are pages for the 3 categories we have for our blog posts. We want to replace the gray bar across the top where it says the name of that category with this image http://www.parallaxdigital.com/wp-content/uploads/2018/09/News-Header-1920.jpg.

The page I need help with: [log in to see the link]