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