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