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