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