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)(19,20)(23,24)(25,26)(27,31)(28,30)(29,36)(32,35)(33,37)(34,39)(38,40)(2,6)(4,7)(9,10)(11,15)(12,14)(13,16)(18,22)(23,24)(25,27,30,35)(26,31,28,32)(29,34,37,40)(33,38,36,39)(1,3,5,8)(2,7,6,4)(9,10,12,14)(11,13,16,15)(17,18,21,22)(19,23,20,24)(25,27)(26,32)(28,31)(29,34)(30,35)(33,39)(36,38)(37,40)(1,3)(2,4)(5,8)(6,7)(9,10)(11,13)(12,14)(15,16)(17,19,21,20)(18,23,22,24)(25,28,30,26)(27,31,35,32)(29,36,37,33)(34,38,40,39)(1,4)(2,3)(5,7)(6,8)(9,11,12,16)(10,13,14,15)(17,20,21,19)(18,24,22,23)(25,29)(26,33)(27,34)(28,36)(30,37)(31,38)(32,39)(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.