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