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