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