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