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