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