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