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