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