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