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