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