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