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