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