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