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