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