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)(15,23)(16,20)(17,21)(18,22)(19,26)(24,28)(25,27) involution — undirected(6,9)(10,12)(13,15)(14,19)(16,18)(17,26)(20,28)(21,23)(22,27)(24,25) involution — undirected(1,2,3,4)(15,16)(18,24)(19,27)(20,23)(22,28)(25,26)(5,7,8,11)(6,10,9,12)(13,16)(14,20)(15,24)(17,25)(18,26)(19,22)(21,27)(23,28)(15,25)(16,26)(18,24)(19,20)(22,28)(23,27) 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.