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