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