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)(11,13)(12,20)(14,15)(16,18)(17,22)(19,21)(23,24)(25,26)(27,36)(28,29)(30,35)(31,33)(32,38)(34,39)(37,40)(1,3,5,8)(2,6,4,7)(9,10,14,15)(11,16,18,13)(12,17,22,20)(19,21,24,23)(25,27,31,38)(26,32,33,36)(28,35,34,40)(29,37,39,30)(1,4,5,2)(3,7,8,6)(10,15)(11,18)(17,20)(19,24)(26,33)(28,34)(32,36)(35,40)(9,11)(10,16)(12,19)(13,15)(14,18)(17,21)(20,23)(22,24)(25,28,31,34)(26,29,33,39)(27,35,38,40)(30,32,37,36)(9,12)(10,17)(11,19)(13,23)(14,22)(15,20)(16,21)(18,24)(25,29)(26,34)(27,37)(28,33)(30,38)(31,39)(32,40)(35,36) involution — undirected(9,13,14,16)(10,11,15,18)(12,21,22,23)(17,24,20,19)(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.