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