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