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