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