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