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