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