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