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