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