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