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