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