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