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