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