How can I make the slider transition automatically?

Edit the page containing the slider (probably your homepage) and locate the slider shortcode e.g.

[slider timeout="0" margins="0,0,15,0"]

Change the "timeout" value of 0 to the number of seconds between slide transitions. So for 6 seconds between each slide it would look like this:

[slider timeout="6" margins="0,0,15,0"]

To view all the slider shortcode options see: http://buddywp.wpengine.com/features/shortcodes/#sc-sliders