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