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