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