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