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)(13,14,19,22)(15,23,21,18)(16,20,26,28)(17,27,24,25)(2,3)(5,6)(7,10)(8,9)(11,12)(13,15,18,14,19,21,23,22)(16,24,27,20,26,17,25,28)(1,2,4,3)(6,9)(10,11)(13,16)(14,20)(15,24)(17,21)(18,27)(19,26)(22,28)(23,25)(1,3,4,2)(5,7,8,12)(6,10,9,11)(16,26)(17,24)(20,28)(25,27)(13,17,18,28,19,24,23,20)(14,16,21,27,22,26,15,25)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.