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