<?php
	// 親カテゴリーのものだけを一覧で取得
	$args = array(
		'parent' => 0,
		'orderby' => 'term_order',
		'order' => 'ASC'
	);
	$categories = get_categories( $args );
?>

<?php foreach( $categories as $category ) : ?>
	<li>
		<a href="<?php echo get_category_link( $category->term_id ); ?>"><?php echo $category->name; ?></a>
	</li>
<?php endforeach; ?>