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