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