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