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