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