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