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