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