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