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