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