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