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