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