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