If you are a Cox customer: If you have a cable tv subscription, you can watch it on the watchespn android or iOS app as well as watchespn.com. If you are in internet only subscriber, you can watch espn3 on a computer at watchespn.com. See here for details from espn. Not sure what you are referring to by "for Saturday".
If you are not a customer, you would need at least an internet subscription to watch it on you computer. Of course, if you are a student or military on an authorized network, it's free, see above link.