Show categories instead posts on index page

Hello. I have a WP theme. It has all posts on the main page. I need to change categories instead posts with saved pagination and design. Can I fix it? If yes how? Thank you.

<?php if ( have_posts() ) : ?>

            <div id="blog-grid" class="row content-grid">
            <?php while ( have_posts() ) : the_post(); ?>
                <div class="<?php echo esc_attr( tdmacro_column_class() ); ?> post-box">
                <?php get_template_part( 'content', get_post_format() ); ?>
                </div><!-- .col -->
            <?php endwhile; ?>
            </div><!-- .row -->

            <?php tdmacro_paging_nav(); ?>

        <?php else : ?>

            <?php get_template_part( 'content', 'none' ); ?>

        <?php endif; ?>

That’s the bit of code with standard WP loop. As I understand, the string get_template_part( ‘content’, get_post_format() ); gets the design of this page. And how can I make the loop for categories and get this design?

p.s. sorry for my english