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