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