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