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