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