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)(15,23)(16,17)(18,21)(19,22)(20,24)(25,28)(26,27)(6,9)(7,11)(13,15)(14,20)(16,24)(17,27)(18,28)(19,26)(21,23)(22,25) involution — undirected(2,4)(5,6)(7,10)(8,9)(11,12)(13,16,19,18)(14,21,22,17)(15,24,26,28)(20,23,25,27)(6,9)(10,12)(13,17,19,21)(14,16,22,18)(15,25,26,20)(23,28,27,24)(5,7,8,11)(6,10,9,12)(13,16,19,18)(14,17,22,21)(15,24,26,28)(20,27,25,23)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.