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