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