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