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