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