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