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)(25,26,31,32)(27,35,36,33)(28,39,40,29)(30,37,38,34)(1,2)(3,4)(5,7)(6,8)(9,10,14,15)(11,16,19,23)(12,20,21,17)(13,18,24,22)(26,32)(27,36)(29,39)(34,37)(1,3)(2,6)(4,7)(5,8)(10,15)(11,19)(12,21)(13,24)(25,27,31,36)(26,33,32,35)(28,37,40,34)(29,38,39,30)(3,8)(4,6)(9,11)(10,16)(12,22)(13,20)(14,19)(15,23)(17,24)(18,21)(25,28)(26,29)(27,37)(30,35)(31,40)(32,39)(33,38)(34,36) 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)(25,29)(26,28)(27,38)(30,36)(31,39)(32,40)(33,37)(34,35)(1,2)(3,4)(5,7)(6,8)(9,13)(10,18)(11,20)(12,23)(14,24)(15,22)(16,21)(17,19)(25,30,31,38)(26,34,32,37)(27,29,36,39)(28,35,40,33)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.