As explained in documentation the module can be styled in many ways and every instance can be styled individually. You are welcome to copy the style from my demo site.

The Twitter module on the demo page has a container that looking at the HTML source is like this:
<div class="twitterbox"><h3>Twitter</h3>{loadposition user5}</div>Then this class is styled in template CSS:
div.twitterbox {
    background: url(../images/twitter-bottom.gif) no-repeat left bottom;
        width: 350px;
        padding: 0 0 20px 10px;
        margin-bottom: 2px;
}
div.twitterbox h3 {
        background: url(../images/twitter-top.gif) no-repeat left top;
        margin-left: -10px;
        padding: 8px 0 0 8px;
        color: #33ccff;
}
You could also add class suffix to that module (for example _twitter) and then have:
div.moduletable_twitter {
    background: url(../images/twitter-bottom.gif) no-repeat left bottom;
width: 350px;
padding: 0 0 20px 10px;
margin-bottom: 2px;
}
div.moduletable_twitter h3 {
background: url(../images/twitter-top.gif) no-repeat left top;
margin-left: -10px;
padding: 8px 0 0 8px;
color: #33ccff;
}
The images:
http://joomla15.sakic.net/templates/rhuk_milkyway/images/twitter-top.gif
http://joomla15.sakic.net/templates/rhuk_milkyway/images/twitter-bottom.gif

The module itself can be styled in custom css file:
http://joomla15.sakic.net/modules/mod_ajaxscroller/mod_ajaxscroller/style57.css
Note 57 here which is the module's ID. You can also edit the global css if you are not running additional instances of the module.

If there are additional questions feel free to ask. If you require personal assistance for styling it please send the access info (admin password and FTP) by email and I'll be glad to help.