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