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