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