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