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