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