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