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