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