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