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