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