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