Automatically add new post to menu

I am setting up a website for a sports brand. It is like a showroom for products but without the webshop thing. I added the products as a post with a category. These categories are listed as a menu.

What I want is… When someone clicks on a category it should load a new page with a menu of all the products (posts) assigned to that category.

I know you can make a custom menu and add the posts. But is there any way WP can do it on its own?

Salming.nl