WordPress Sitemap with Custom Post Types

<h2 id="posts">My Post Type</h2>
            <ul>
            <?php
            $terms = get_terms( 'my_taxonomy', 'orderby=name' );
            foreach ($terms as $term) {
            echo "<li><h3>".$term->name."</h3>";
            echo "<ul>";
            $args = array(
                'post_type' => 'my_posttype',
                'posts_per_page' => -1,
                'tax_query' => array(
                    array(
                        'taxonomy' => 'my_taxonomy',
                        'field' => 'slug',
                        'terms' => $term->slug
                    )
                )
            );
            $new = new WP_Query($args);
            while ($new->have_posts()) {
            $new->the_post();
            echo '<li><a href="'.get_permalink().'">'.get_the_title().'</a></li>';
            }
            echo "</ul>";
            echo "</li>";
            } ?>
            </ul>