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