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