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