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