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