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