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