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