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