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