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