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