you need a list of posts by author in the menu? or in a custom page? Please make this clear in your question.
For the menu you can build a custom menu and style it with css to fit your needs.
For a page you can build a custom query:
<?php
// Get the authors from the database ordered by user nicename
global $wpdb;
$site_admin = ""; // enter Admin ID to exclude
$query = "SELECT ID, user_nicename from $wpdb->users WHERE ID != '$site_admin' ORDER BY user_nicename";
$author_ids = $wpdb->get_results($query);
// Loop through each author
foreach($author_ids as $author) :
// Get user data
$curauth = get_userdata($author->ID);
// Get link to author page
$user_link = get_author_posts_url($curauth->ID);
?>
<ul>
<li><?php echo $curauth->nickname; ?></li>
<ul>
<?php $author_query = new WP_Query( 'author='.$curauth->ID.'&posts_per_page=-1&' );
while ( $author_query->have_posts() ) : $author_query->the_post(); ?>
<li><?php the_title(); ?></li>
<?php endwhile; wp_reset_postdata(); ?>
</ul>
</li>
</ul>
<?php endforeach; ?>
you can put this in a custom page.
Also if you need to exclude the Administrator or any other user from the query, use the $site_admin
var.