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