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