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