1. Target the menu like you would normally do with the MMenu WordPress plugin.
2. Ensure your category listing on the page looks like this:

   <nav id="main-menu">
   <ul><?php wp_list_cats();?></ul>
   </nav>

3. Now for the final part, add this to your functions.php file so the MMenu active class can be implemented in the category layout.

   add_filter( 'wp_list_categories', function( $html ) {
    return str_replace( ' current-cat', ' current-menu-item', $html );
   });

html.mm-opened { overflow: auto !important;}