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