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)(11,16)(12,18)(13,19)(14,20)(15,17)(21,24)(22,23)(26,27)(28,35)(32,34)(36,40)(9,11)(10,16)(12,13)(14,17)(15,20)(18,19)(21,22)(23,24)(25,26,30,27)(28,33,35,31)(29,32,37,34)(36,39,40,38)(1,2)(3,5)(4,6)(7,8)(10,17)(11,20)(13,21)(18,23)(25,27,30,26)(28,33,35,31)(29,32,37,34)(36,38,40,39)(3,7)(5,8)(9,12)(10,18)(11,21)(13,20)(14,19)(15,22)(16,24)(17,23)(25,28)(26,31)(27,33)(29,36)(30,35)(32,38)(34,39)(37,40) involution — undirected(1,3,4,7)(2,5,6,8)(9,13,15,21)(10,19,17,24)(11,12,20,22)(14,23,16,18)(25,29,30,37)(26,32,27,34)(28,36,35,40)(31,38,33,39)(1,2)(3,5)(4,6)(7,8)(9,14)(10,11)(12,19)(13,23)(15,16)(17,20)(18,21)(22,24)(25,28)(26,31)(27,33)(29,36)(30,35)(32,38)(34,39)(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.