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