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