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