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