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