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