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