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