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