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