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