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