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