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