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