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)(13,14,17,20)(15,21,22,28)(16,24,26,19)(18,25,27,23)(1,2)(3,4)(5,6)(7,11)(8,10)(9,12) involution — undirected(5,7,8,12)(6,9,10,11)(13,15,17,22)(14,18,20,27)(16,25,26,23)(19,28,24,21)(2,4)(7,12)(9,11)(15,22)(18,27)(21,28)(23,25) involution — undirected(6,10)(9,11)(15,22)(18,27)(21,28)(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.