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