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