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