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