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)(11,17)(12,15)(13,18)(14,16)(19,24)(20,22)(21,23)(25,26)(27,36)(28,39)(29,40)(30,35)(31,32)(33,38)(34,37)(1,3,5,8)(2,6,4,7)(9,11,14,12)(10,15,16,17)(13,19,21,20)(18,22,23,24)(25,27)(26,30)(28,37)(29,38)(31,35)(32,36)(33,34)(39,40)(1,2,5,4)(3,6,8,7)(10,16)(15,17)(18,23)(22,24)(26,32)(27,35)(28,38)(34,40)(9,10)(11,15)(12,17)(13,18)(14,16)(19,22)(20,24)(21,23)(25,28,31,38)(26,33,32,39)(27,37,35,29)(30,34,36,40)(1,4,5,2)(3,7,8,6)(9,12,14,11)(10,17,16,15)(13,20,21,19)(18,24,23,22)(25,29,31,37)(26,34,32,40)(27,38,35,28)(30,33,36,39)(9,13,14,21)(10,18,16,23)(11,19,12,20)(15,22,17,24)(25,30,31,36)(26,35,32,27)(28,34,38,40)(29,39,37,33)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.