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