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