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