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