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