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