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