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