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