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