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