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