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