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