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