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