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