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