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