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