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