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