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