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