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