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