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)(25,26,31,34)(27,33,30,29)(28,36,39,32)(35,37,38,40)(1,2)(3,8)(4,6)(5,7)(12,19)(16,22)(18,23)(20,24)(25,27,31,30)(26,29,34,33)(28,35,39,38)(32,37,36,40)(1,3,5,4)(2,6,7,8)(10,15)(11,17)(16,22)(18,23)(25,28,31,39)(26,32,34,36)(27,35,30,38)(29,37,33,40)(9,11)(10,13)(12,18)(14,17)(15,21)(16,20)(19,23)(22,24)(25,28)(26,32)(27,35)(29,37)(30,38)(31,39)(33,40)(34,36) involution — undirected(1,4,5,3)(2,6,7,8)(9,12,14,19)(10,16,15,22)(11,18,17,23)(13,20,21,24)(25,29)(26,27)(28,37)(30,34)(31,33)(32,35)(36,38)(39,40)(1,2)(3,6)(4,8)(5,7)(9,13)(10,11)(12,20)(14,21)(15,17)(16,18)(19,24)(22,23)(25,30,31,27)(26,33,34,29)(28,38,39,35)(32,40,36,37)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.