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