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