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