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