Sorry, to change the widget, you would basically have to hack the plugin. Which you can certainly do, but then if we update the plugin, you will loose any changes you make to the widget.
If you still want to change the loop on the widget, then you would need to edit the speaker-widget.php located in the includes directory.
The loop for that looks something like this (towards the bottom of the file):
global $post;
$args = array(
'post_type' => 'cr3ativspeaker',
'order' => $orderby,
'posts_per_page' => $itemstodisplay
);
query_posts($args);
You could just add the orderby to it to make it look like this:
global $post;
$args = array(
'post_type' => 'cr3ativspeaker',
'order' => $orderby,
'posts_per_page' => $itemstodisplay,
'orderby' => 'title'
);
query_posts($args);