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