This is possible but requires that you edit the
card.php file found here:
Add this line of code where you want the categories to be shown:
<?php $entry->getCategoryBlock( array( 'separator' => ', ', 'before' => '<span>', 'after' => '</span>' ) ); ?>
Rather than overwrite the existing
card.php file, you should follow the advice in this QuickTip so your change is not lost if the the template is updated.