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