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