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