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