One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,8)(9,11)(10,12)(13,14,18,22,19,21,27,28)(15,17,23,26,20,16,24,25)(1,2)(3,4)(5,7)(6,10)(8,11)(9,12)(13,15,19,20)(14,17,21,16)(18,23,27,24)(22,26,28,25)(2,4)(13,16,19,17)(14,20,21,15)(18,26,27,25)(22,23,28,24)(6,11)(7,12)(13,17,19,16)(14,15,21,20)(18,25,27,26)(22,24,28,23)(5,8,9,10)(6,7,11,12)(14,21)(15,20)(22,28)(23,24)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.