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