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