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