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