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