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