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