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