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