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