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)(13,14,18,16)(15,20,23,22)(17,19,25,21)(24,26,28,27)(5,6)(7,11)(8,10)(9,12)(14,19)(16,21)(17,25)(20,26)(22,27)(24,28) involution — undirected(2,4)(5,7,8,12)(6,9,10,11)(13,15)(14,20)(16,22)(17,24)(18,23)(19,26)(21,27)(25,28)(7,12)(9,11)(13,16,18,14)(15,22,23,20)(17,21,25,19)(24,27,28,26)(6,10)(9,11)(15,23)(20,22)(24,28)(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.