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