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