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)(13,14,20,28,19,25,18,24)(15,16,17,21,26,27,22,23)(5,6)(7,11)(8,10)(9,12)(13,15,19,26)(14,21,25,23)(16,24,27,28)(17,20,22,18)(2,4)(5,7)(6,9)(8,12)(10,11)(13,16,19,27)(14,22,25,17)(15,24,26,28)(18,23,20,21)(7,12)(9,11)(13,17,18,15,19,22,20,26)(14,23,24,27,25,21,28,16)(6,10)(9,11)(13,18,19,20)(14,24,25,28)(15,17,26,22)(16,21,27,23)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.