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