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