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