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