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)(13,14,17,22)(15,23,25,27)(16,20,18,21)(19,26,28,24)(2,4)(13,15,17,25)(14,19,22,28)(16,26,18,24)(20,23,21,27)(6,9)(7,12)(10,11)(13,14)(15,23)(16,20)(17,22)(18,21)(19,24)(25,27)(26,28) involution — undirected(6,10)(9,11)(13,16,17,18)(14,20,22,21)(15,24,25,26)(19,27,28,23)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.