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)(15,19,25,18)(16,17,24,28)(21,26,27,22)(1,2)(3,4)(6,10)(11,12)(13,15)(14,19)(16,21)(17,26)(18,23)(20,25)(22,28)(24,27) involution — undirected(5,7,9,8)(6,11,10,12)(13,16,19,22,20,24,18,26)(14,21,15,17,23,27,25,28)(2,4)(5,8,9,7)(6,12,10,11)(13,17,18,21,20,28,19,27)(14,22,25,16,23,26,15,24)(6,10)(11,12)(13,18,20,19)(14,15,23,25)(16,26,24,22)(17,27,28,21)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.