One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,6,4)(3,7,5,8)(9,10,15,17)(11,18,14,16)(12,13,22,23)(19,20,21,24)(25,26,30,31)(27,28,33,36)(29,32,37,38)(34,35,39,40)(1,3,6,5)(2,7,4,8)(9,11,15,14)(10,16,17,18)(12,21,22,19)(13,20,23,24)(26,31)(27,33)(32,38)(34,39)(1,3,6,5)(2,8,4,7)(10,17)(12,22)(16,18)(19,21)(25,27)(26,28)(29,34)(30,33)(31,36)(32,35)(37,39)(38,40)(1,4,6,2)(3,7,5,8)(9,12)(10,13)(11,19)(14,21)(15,22)(16,24)(17,23)(18,20)(25,28)(26,27)(29,35)(30,36)(31,33)(32,34)(37,40)(38,39)(1,5,6,3)(2,7,4,8)(9,13)(10,12)(11,20)(14,24)(15,23)(16,21)(17,22)(18,19)(25,29,30,37)(26,32,31,38)(27,34,33,39)(28,35,36,40)(9,14,15,11)(10,16,17,18)(12,19,22,21)(13,20,23,24)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.