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