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