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