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