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