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