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