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