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