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