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