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