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