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