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