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