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