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