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