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