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