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