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