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