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