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