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