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