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