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