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