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