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