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