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