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