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