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