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