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