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