One vertex per element, one color per generator, with an edge from x to x·s.
(5,6,9,8,11,7,10,12)(13,14,20,28,19,21,18,22)(15,23,26,25,17,16,24,27)(1,2)(3,4)(5,7)(6,11)(8,9)(10,12)(13,15,19,17)(14,16,21,23)(18,26,20,24)(22,27,28,25)(2,4)(5,8,11,12)(6,10,7,9)(13,16)(14,15)(17,21)(18,27)(19,23)(20,25)(22,26)(24,28)(5,6)(7,11)(8,10)(9,12)(13,17,19,15)(14,16,21,23)(18,24,20,26)(22,27,28,25)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.