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