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