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