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