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