Displaying custom-taxonomy-terms sorted by parent/child-hierarchy?

I have a custom post type with a custom taxonomy (to show some "best practice" examples on my website). On the single-post-page (single-bestpractice.php) I wanted to show all the terms (categories) like this:

Parent: Child, Child, Child

I tried this code:

$customPostTaxonomies = get_object_taxonomies('bestpractice');
if (count($customPostTaxonomies)  0) {
    foreach ($customPostTaxonomies as $tax) {
        $args = array(
            'orderby' = 'name',
            'show_count' = 0,
            'pad_counts' = 0,
            'hierarchical' = 1,
            'taxonomy' = $tax,
            'title_li' = ''
        );  
        wp_list_categories( $args );
    }
}

which outputs:

Child, Child, Parent, Child,

…so, is there a way to sort it by parent/child and make the parent one start with a ":" and remove the "," of the last child?

thanx, Jochen