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