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