What you want to do is repeat the function multiple times in your template.
<table border="0" style="padding:4px;" width="100%" cellspacing="0" cellpadding="0">
<tr>
<td class="featured-box" style="padding:0;">
<?php if (function_exists('rps_show')) echo rps_show($category_ids="4", $total_posts="1", $post_include_ids, $post_exclude_ids); ?>
</td>
<td class="featured-box" style="padding:0;">
<?php if (function_exists('rps_show')) echo rps_show($category_ids="5", $total_posts="1", $post_include_ids, $post_exclude_ids); ?>
</td>
<td class="featured-box" style="padding:0;">
<?php if (function_exists('rps_show')) echo rps_show($category_ids="2", $total_posts="1", $post_include_ids, $post_exclude_ids); ?>
</td>
</tr>
</table>
Something like the above will give you 3 sliders, though the current settings are pulling from only one category ID.
If you want the top slider to show multiple posts, change the number of posts (to 3, 5, or whatever) and if you want it to pull from multiple categories, just add $category_ids="2, 3, 5" or whatever you want to do.
As far as changing the styling for each one, do that in CSS. Just put each box in a different div, or create a div #RPS and then multiple classes .box1, .box2 et cetera, and style everything that way.
