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