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