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