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