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