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