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