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