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