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