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