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