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