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