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