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