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