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