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