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