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