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