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