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