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