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