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