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