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