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