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