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