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