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