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