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