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