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