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