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