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