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