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