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