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