Show one page with all categories and posts

Hi guys,

I want to create a link to a page where all categories are shown with post headings under it, how do i do this?

I can link to individual category pages by using domainname/category/categoryname, but I can't link to a all categories page.

How do I do this? Maybe sitemap would be a solution but already using that in a specific way, and plugin has only one option.

Is there a standard way or how could i Create this?

thanks again in advance guys!