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