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