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