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