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