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